Re: [PATCH] HID: pidff: bound the unit exponent rescaling loop

[Tomasz Pakuła]

On Mon, 2026-11-02 at 22:40 +0800, Shengzhuo Wei wrote:
> Hi Tomasz,
> 
> Thanks for testing and reviewing the patch.
> 
> > Should we maybe add a warning to the driver that the time exponent might
> > be out of a sane range? Sane range being, say, 10 to 0? This of course
> > would have to happen during init stage not to spam dmesg.
> 
> For the initialization-time warning, would -8 to 0 be a reasonable
> exponent range?

Yes, I meant to say -10 (not positive 10 obviously) but -8 seems like a
better fit here.

> - -8 is the lowest exponent in the commonly used signed 4-bit HID
>   encoding.
> - 0 allows a time unit of one second.
> - Positive exponents 1 through 7 would give time units of ten seconds
>   or more, which seem unusually coarse for force-feedback effects.
> 
> This would only be a warning threshold: the driver would still accept
> the device and leave the rescaling behavior unchanged.
> 
> Does that match what you had in mind, or would you prefer a different
> range?

Yup, that range is great.

> 
> Thanks,
> Shengzhuo